Service personnel for power companies and the like often utilize a telescopic pole commonly referred to as a "shotgun stick" or a "hot stick" for installing hot line clamps and manipulating other tools when working on or around energized electrical distribution lines. Telescoping poles of this type are disclosed in my earlier U.S. Pat. Nos. 2,980,456, 3,103,375 and 3,788,691. While poles of this type are generally satisfactory, nevertheless additional modifications have been incorporated therein to further improve upon the existing design and thereby make the pole safer and easier to use.
One problem with telescopic poles is the occasional breakage of the locking pins. When the pole is being retracted, the locking pin is manually released and, with the pole in an approximate vertical position, the pole sections are then allowed to freely slidably telescope one within the other due to the urging of gravity. This results in an upper pole section moving downwardly with sufficient speed so that it impacts against the locking device of the lower pole section, whereby the locking pin is often fractured. While a pole failure of this type is normally caused by a misuse of the pole, particularly an improper handling of the pole during collapsing thereof, nevertheless it is desirable to improve upon the pole structure so as to eliminate failures caused by misusage of this type.
In addition, service personnel working with poles of this type have often expressed a fear that moisture or contamination might accumulate within the individual pole sections and cause a potentially unsafe condition due to electrical arcing. While no instance of this happening is known, nevertheless designing the pole to eliminate this possibility greatly enhances both the safety and acceptability of the pole.
Thus, it is an object of the present invention to provide an improved telescopic pole adapted for use with electrical conductors and the like, which pole overcomes the above-mentioned shortcomings. More specifically, it is an object of the present invention to provide:
1. An improved telescoping pole which includes an integral dampening structure coacting between the adjacent pole sections for controlling the relative telescoping movement between the sections during collapsing of the pole.
2. An improved telescoping pole, as aforesaid, which is provided with seals between the locking devices and the tubular pole sections so that each pole section functions as a pneumatic dashpot for regulating the maximum rate at which the pole sections can be telescopically collapsed due to the urging of gravity. 3. An improved telescoping pole, as aforesaid, which has an air bleed hole communicating with the interior of each pole section for controlling the collapsing rate of the pole sections, and for preventing the accumulation of moisture and contamination within the pole sections.
4. An improved telescoping pole, as aforesaid, which provides greater safety to the operating personnel, which is more durable in operation, which possesses the ease of operation of existing poles, and which is economical to manufacture and assemble.